Protective helmet



FIG. 1 is a front perspective view of a protective helmet, showing mynew design;

FIG. 2 is a front elevation view of the protective helmet of FIG. 1;

FIG. 3 is a rear elevation view of the protective helmet of FIG. 1;

FIG. 4 is a right side elevation view of the protective helmet of FIG.1;

FIG. 5 is a left side elevation view of the protective helmet of FIG. 1;

FIG. 6 is a top plan view of the protective helmet of FIG. 1; and,

FIG. 7 is a bottom plan view of the protective helmet of FIG. 1.

The broken lines shown in the drawings represent portions of theprotective helmet that form no part of the claimed design.

CLAIM The ornamental design for a protective helmet, as shown anddescribed.